Fluid–fluid devices: A device that uses the momentum of one fluid stream to entrain and transport another fluid is called a/an

Introduction / Context:
Many process plants employ momentum-transfer devices where a high-velocity motive fluid entrains a secondary fluid. These devices have no moving parts and are widely used for pumping, mixing, vacuum generation, and gas–liquid contacting.

Given Data / Assumptions:

• A high-pressure motive fluid accelerates through a nozzle.
• Low-pressure suction fluid is entrained and mixed.
• Diffuser section converts kinetic energy back to pressure for discharge.

Concept / Approach:
The generic names are jet pump, ejector, or eductor. They rely on Bernoulli acceleration in the nozzle, momentum mixing in the throat, and pressure recovery in the diffuser. Typical motive/suction combinations include steam–gas, liquid–liquid, or liquid–gas.

Step-by-Step Solution:
Identify device principle: momentum transfer from motive to suction stream.Match to terminology: jet pump/ejector/eductor.Select the option naming this device.

Verification / Alternative check:
Standards and vendor catalogs consistently use “jet pump,” “ejector,” and “eductor” for this principle. Blowers and compressors are mechanical rotating equipment; an “acid egg” is a pressure vessel for liquid transfer, not a momentum device.

Why Other Options Are Wrong:

• Blower/rotary compressor: add energy via rotating elements, not via motive jet entrainment.
• Acid egg: uses pressure differential in a vessel; not a jet ejector.
• Vent cap: unrelated to pumping.

Common Pitfalls:
Confusing ejectors (no moving parts) with compressors (mechanical). Also, assuming “pump” always implies mechanical impellers.

Final Answer:
Jet pump (ejector/eductor)